Effects of different methods and severity of growing period feed restriction on growth and laying performance of white Leghorns.

Two experiments were conducted to study the effects of different methods of feed restriction and severity of feed restriction during the growing period on pullet growth and laying performance of White Leghorns. In Experiment 1, ad libitum feeding of the low protein diet (supplemented with amino acids) was the only treatment among four feed restriction treatments that did not significantly (P greater than .05) influence growing period feed consumption and body weight gain. The smallest body weight gain was obtained among birds subjected to the daily restrictive feeding (DRF) treatment. Ad libitum feeding of the low energy diet resulted in a significantly (P less than .05) poorer growing period feed efficiency than any other treatment. Both energy and protein utilization efficiencies for body weight gain were significantly (P less than .05) hindered by the skip feeding treatment. Although DRF birds consistently had higher egg production from 36 to 76 weeks of age than birds in any other group, overall average percent hen-day egg production from 20 to 76 weeks of age was not significantly (P greater than .05) improved by the DRF treatment. Also, in Experiment 2, various levels of DRF during the growing period did not significantly (P greater than .05) improve average percent hen-day egg production. Laying house mortality, feed efficiency, and egg weight were not significantly (P greater than .05) different among treatments (Experiments 1 and 2). Results of these experiments indicate that DRF was the most effective method of controlling growth rate and that neither method of feed restriction nor severity of feed restriction during the growing period significantly (P greater than .05) improved laying performance.